Caption: Whitney's cotton gin patent. Restored patent drawings, dated 14th March 1794, of the cotton gin machine design by US inventor Eli Whitney (1765-1825). Raw cotton is placed in the machine and pulled through a mesh, using the rotating handle on the side. The mesh separates the cotton fibres from the seeds. This machine was a key invention of the industrial revolution, boosting the agricultural economy of the southern US states. However, the patent was not validated until 1807, and the costs of fighting patent infringements drove Whitney's company out of business by 1897.